sl.cpp: In function 'int main()': sl.cpp:50: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result sl.cpp:51: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result sl.cpp:53: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result sl.cpp:56: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result sl.cpp:58: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result sl.cpp:52: warning: 'z' may be used uninitialized in this function /tmp/cccNg5hb.o: In function `main': sl.cpp:(.text+0x390): warning: the `gets' function is dangerous and should not be used.